Max heart rate
178bpm
Tanaka
220 − age
177bpm
classic
Zone 2
107–125bpm
aerobic base
Vigorous from
137bpm
about 77% of max
Show the math
Max HR = 208 − 0.7 × 43 = 178 bpm
Heart rate zones at 43
| Zone | BPM | % of max | Feels like |
|---|---|---|---|
| Zone 1 · Recovery | 89–107 | 50–60% | Easy, conversational |
| Zone 2 · Aerobic base | 107–125 | 60–70% | Steady, can still talk |
| Zone 3 · Tempo | 125–142 | 70–80% | Comfortably hard |
| Zone 4 · Threshold | 142–160 | 80–90% | Hard, short phrases |
| Zone 5 · Max effort | 160–178 | 90–100% | All-out, seconds to minutes |
Karvonen zones by resting heart rate
| Resting HR | Zone 1 | Zone 2 | Zone 3 | Zone 4 |
|---|---|---|---|---|
| Resting 55 | 116–129 | 129–141 | 141–153 | 153–166 |
| Resting 65 | 121–133 | 133–144 | 144–155 | 155–167 |
| Resting 75 | 126–137 | 137–147 | 147–157 | 157–168 |
Karvonen: resting + (max − resting) × intensity. More personal if you know your resting rate.
How to use it
- Enter your numbers. Switch between US and metric units at any time.
- Results update as you type, and the formula is shown so you can check it.
- Copy the link, save the plan on this device, or print it for your next appointment.
Want a clinician to look at these numbers?We know licensed clinicians in every state. If you ask, one can reach out to you. Get matched
These are estimates, not a diagnosis. A clinician can account for your health history and medicines.
Other ages
Common questions
What is a good heart rate zone for a 43-year-old?
Zone 2, about 107 to 125 bpm, builds aerobic base. Moderate exercise sits around 114 to 135 bpm.
What is the max heart rate at 43?
About 178 bpm by the Tanaka formula, or 177 by 220 minus age. Individual max can differ by 10 or more beats.